HEATED SEATS NOT WORKING

Both front heated seats are not working. When I push the heated seat button the HI indicator light comes on, but no heat. The LO indicator light will not come on. I can not turn the HI indicator light off by pushing the heated seat button, in order to turn the light off I have to turn the key off.
All the connections under both seats seem to be tight.
Thank You for any help that you may offer.
Chuck Gunn